Improvement in locomotive fire-box crowns



H. C. DARBY.

Locomotive Fire-Bax Crowns.

Patented June 24,187.13.

0000 o 0000 O oooo @dooo 0 1000 0000 b oooo 0 00000 O 0000 11a! Tiara.

d1 a F AM. PHOT O-LlTi/OGRAPHIC 00 MC (asaoms Pliocess) three sections.

UNITED STATES PATENT FFIGE.

HENRY c. DARBY, on WYANDOTTE, KANSAS.

IMPROVEMENT IN LOCQMOTIVE FIRE-BOX CRQWNS.

Specification forming part of Letters Patent No. 140,251, dated June 24, 1873; application filed April 4, 1873.

do'tte and State of Kansas, have invented certain'Improvements in Locomotive Fire-Box Crowns, of which the following is a specifica- 7 tion:

My invention relates to the construction of the crown or top portion of the tire-box by means of an arch and bolts in such a manner as to supersede the necessity of crown bars and washers, securing the same amount of strength by the use of a much less weight of metal and at the same time greatly increasing the radiation of heat through the crown-plate to the water in the boiler.

The object of the invention is to dispense with the necessity of the crown bars and wash ers, and thus secure a greater heating-surface upon the crown-plate and increase the radiation of heat through the crown-plate to the water in the boiler.

Figure 1 is a sectional side view of crown as attached to the crown-plate and fire-box. Fig. 2 is a half-sectional end view of fire-box, showing section through center of crown,with the connecting-bolts in proper position. Fig. 3 is a plan, showing top view of crown as complete, with the heads of the connecting-bolts and rivets, with flange or T-iron bar at intersections of arch. Fig. 4: is a View of the connecting-bolt passing through the arch and crown-plate, showing position of the bolt in crown-plate and arch.

The erownis composed of an arch, A, constructed of three-eighths-inch boiler-iron, in These sections are joined or connected by means of a flange, a, made by turning up either edge of each section and closely riveting the two together above the arch; or'a T-iron bar, B, may be used instead of the flange and riveted upon the arch over the joints, thus affording an opportunity to attach braces from the top of the arch to the wagoirtop of the boiler. This arch is confined at each end by rivets t0 the crown-plate O and through the fiuesheet and back sheet of the firebox, as shown by Fig. 1. Where the sections of the arch are joined a three-inch opening is cut, thereby affording an opportunity for confining the crown-sheet temporarily to the fire-box before fitting the arch, also affording an opportunity for cleaning the crown-sheet by washing or otherwise. The arch is supported and connected to the crown-sheet by ordinary stay-bolts D tapped through the arch and crown-plate and riveted at both ends, beneath the crown-plate and on top of the arch, as shown by Figs. 2 and 4 of drawing.

My invention dispenses with the crown-bars, as above set forth, thus securing four inches more space between the crown-plate and the arch than is allowed with the crown-bars now Witnesses:

JAMES A. ORUIsE, M. W. BEAcH. 

